Isobe Onsen

Gunma hillside onsen built around a 365-step stone staircase. Famous 'gold' (iron-bearing) and 'white' (sulfate) waters.

Quiet Gunma valley onsen designated 国民保養温泉地 #1 in 1954. The 'forty-thousand cures' name nods to its medicinal reputation.

One of the three great onsen of Japan (Sanmeisen). Famously hot, acidic waters; the wooden yubatake in the town center funnels source water into cooling channels.

Japan's highest onsenchi, at 1,800 m on the slopes of Mt. Shirane in Gunma. Strongly acidic milky-white sulfur waters (pH 2.5) from one of the country's most active geothermal fields, with rotenburo open to alpine views year-round.